Getting a new copy of a game(Xbox 360)

So lately I started having "unable to read disc" errors for MW2, starting a couple months ago. There's really no scratches on the disc and it barely left the console(with that said, could the overheating Xbox cause damage?).

Anyways, does anyone know if it's possible to get another copy or something without having to buy the game again or illegal means?

Well this was a repaired regular unit(got it back like 3 months ago) and an original MW2 disc I bought around the time it had just came out. The disc doesn't have a uniform reflection(looks like its distorted), and I honestly made it worse by trying to "clean" it.

Anyways, I guess I'll be contacting MS about this. I haven't received any emails either.